docs(gate): document the merge-time rust-gate bypass

AGENTS.md

@@ -142,7 +142,7 @@ npm run serve               # Build and run the Rust server
 **On WSL machines, "the desktop app" means the Windows app.** Always build, install, and launch the Windows Electron app (`npm run electron:build:win` + the NSIS installer) — never a Linux AppImage/deb under WSLg. The Windows build must run as a native Windows process so Cargo produces a native `freshell-server.exe`; drive it from WSL by rsyncing to a Windows-local dir and running Windows npm via `cmd.exe` — see [docs/development/windows-electron-build.md](docs/development/windows-electron-build.md).
 
 ### Testing
-Pre-push gate: every `git push` runs the cheap local checks (cargo fmt, typecheck, clippy, plus targeted `cargo test` for the changed Rust crates and their dependents when the push touches Rust) filtered by what the push changes — see [docs/development/pre-push-gate.md](docs/development/pre-push-gate.md). Bypass: `git push --no-verify`. Server-side backstop: PRs touching Rust must pass the required `rust-gate` check (workspace `cargo test`, `.github/workflows/rust-tests.yml`); PRs with no Rust changes pass it instantly.
+Pre-push gate: every `git push` runs the cheap local checks (cargo fmt, typecheck, clippy, plus targeted `cargo test` for the changed Rust crates and their dependents when the push touches Rust) filtered by what the push changes — see [docs/development/pre-push-gate.md](docs/development/pre-push-gate.md). Bypass: `git push --no-verify`. Server-side backstop: PRs touching Rust must pass the required `rust-gate` check (workspace `cargo test`, `.github/workflows/rust-tests.yml`); PRs with no Rust changes pass it instantly. Merge-time bypass for a red `rust-gate`: `gh pr merge <n> --merge` from the owner account (ruleset `pull_request`-mode bypass actor).
 Backend fallback policy: never silently fall back from the configured cloud test backend to local — if the cloud path fails, fix it; a local-backend run may substitute only when the cloud path cannot be fixed AND the user explicitly approves.
 
 ```bash

docs/development/pre-push-gate.md

@@ -26,6 +26,7 @@ Vitest/e2e/electron lanes and the real-transport clippy lanes stay with the norm
 - Bypass (emergencies only): `git push --no-verify`
 - Disable for one push: `FRESHELL_PREPUSH=0 git push ...`
 - See routing without running checks: `FRESHELL_PREPUSH_DEBUG=1 git push --dry-run ...`
+- Bypass the server-side `rust-gate` (merge-time, PRs only): the owner account is a `pull_request`-mode bypass actor on the "Protect Main - No Direct Push" ruleset, so merging with a red or missing `rust-gate` is just `gh pr merge <n> --merge` from that account — GitHub records it as a ruleset bypass with an audit entry. This is the explicit escape hatch for landing on a red base; it does NOT unlock direct pushes to main.
 - If a lane's tooling is unavailable it is skipped with an accurate warning (not a failure). The hook self-heals stripped-environment contexts (ssh/agents/IDEs/cron): it sources `~/.nvm/nvm.sh` when `npm` is missing from PATH, and adds `~/.cargo/bin` when `cargo` is missing.
 
 ## Setup